Porting tg painting code. (#12305)

* Porting tg painting code.

* yes.

code/modules/photography/photos/frame.dm

@@ -40,6 +40,7 @@
 /obj/item/wallframe/picture/examine(mob/user)
 	if(user.is_holding(src) && displayed)
 		displayed.show(user)
+		SEND_SIGNAL(user, COMSIG_ADD_MOOD_EVENT, "artok", /datum/mood_event/artok)
 		return list()
 	return ..()
 
@@ -109,6 +110,7 @@
 /obj/structure/sign/picture_frame/examine(mob/user)
 	if(in_range(src, user) && framed)
 		framed.show(user)
+		SEND_SIGNAL(user, COMSIG_ADD_MOOD_EVENT, "artok", /datum/mood_event/artok)
 		return list()
 	return ..()
 

code/modules/tgui/states/physical.dm

@@ -2,7 +2,7 @@
   * tgui state: physical_state
   *
   * Short-circuits the default state to only check physical distance.
- **/
+  */
 
 GLOBAL_DATUM_INIT(physical_state, /datum/ui_state/physical, new)
 
@@ -22,3 +22,28 @@ GLOBAL_DATUM_INIT(physical_state, /datum/ui_state/physical, new)
 
 /mob/living/silicon/ai/physical_can_use_topic(src_object)
 	return UI_UPDATE // AIs are not physical.
+
+/**
+ * tgui state: physical_obscured_state
+ *
+ * Short-circuits the default state to only check physical distance, being in view doesn't matter
+ */
+
+GLOBAL_DATUM_INIT(physical_obscured_state, /datum/ui_state/physical_obscured_state, new)
+
+/datum/ui_state/physical_obscured_state/can_use_topic(src_object, mob/user)
+	. = user.shared_ui_interaction(src_object)
+	if(. > UI_CLOSE)
+		return min(., user.physical_obscured_can_use_topic(src_object))
+
+/mob/proc/physical_obscured_can_use_topic(src_object)
+	return UI_CLOSE
+
+/mob/living/physical_obscured_can_use_topic(src_object)
+	return shared_living_ui_distance(src_object)
+
+/mob/living/silicon/physical_obscured_can_use_topic(src_object)
+	return max(UI_UPDATE, shared_living_ui_distance(src_object)) // Silicons can always see.
+
+/mob/living/silicon/ai/physical_obscured_can_use_topic(src_object)
+	return UI_UPDATE // AIs are not physical.